AstraZeneca said the US FDA issued a Complete Response Letter (CRL) to the supplemental New Drug Application (sNDA) for Saphnelo (anifrolumab) subcutaneous administration, which is being developed for systemic lupus erythematosus (SLE). AstraZeneca stated that information requested in the CRL has already been submitted and an FDA decision on the updated filing for Saphnelo SC is expected in H1 2026, while the intravenous (IV) Saphnelo remains commercially available.
Saphnelo is a human monoclonal antibody that targets the type I interferon receptor and inhibits downstream signalling, a pathway implicated in the pathogenesis of SLE, a chronic autoimmune disease marked by multi-organ inflammation and immune dysregulation. The intravenous formulation of Saphnelo was approved in the United States in 2021, for adults with moderate to severe SLE based on clinical trial evidence demonstrating reductions in disease activity compared with standard care. The subcutaneous formulation was intended to offer an alternative route of administration to improve convenience and broaden patient access, particularly in community settings.
The anifrolumab programme originated at Medimmune before being acquired by AstraZeneca as part of its broader immunology portfolio; AstraZeneca is responsible for global clinical development and regulatory strategy for both the intravenous and subcutaneous formulations. The company has previously secured regulatory approvals for Saphnelo intravenous in the US, European Union, and other regions, establishing the molecule as an approved treatment option in SLE.